Brush-holder



A. T. LOCHNER.

BRUSH HOLDER.

APPLICATION FILED JULY 17, 1919.

Patented Nov. 1, 1921, V

fig?

A l E F :iL- JJJEI IEEWA t g I UNITED STATES PATENT OFFICE.

ALBERT 'rnoms Locum or cmoaeo, ILLIN I s AssIGNOR TO wonaox ELECTRIG moon oom'om'rxon, or CHICAGO, rumors, A CORPORATION or ILLINOIS.

BRUSH-HOLDER.

To all whom it may concern:

Be it known that I, ALBERT THOMAS LOCH- NER, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Brush-Holders, of which the followin is a specification.

My invention relates to holders for the brushes of electric motors. I have illustrated it in connection with a motor mounted in the cylindrical casing of an electric hand tool but it is applicable for use in connection with any type of motor.

One of the objects of my invention is to construct a brush holder comprising as few parts as possible, very cheap to manufacture and simple and easy to assemble.

In the accompanying drawings, Figure 1 is a side view partly in section of the rear end of an electric tool showing the application of a device according to my invention to an electric motor in the casing of the tool. Fig. 2 is a section on the line 22 of Fig. 1. Fig. 3 is a view looking downward at the upper clip shown in F ig, 2, and Fig. 4 is a perspective View of the 'I'hain metal member of the brush holder.

In the embodiment of my invention selected for illustration,- the clip 10 comprising the main element of my brush holder is formed of a single flat piece of sheet metal bent up as shown in Fig. 4 to provide at one b end of said clip a rectangular transversely extending passageway 11 partly open on one side, and at the opposite end a small upwardly projecting ear 12 terminating in a short hook-shaped extension 13.

Referring to Fig. 3, the metal clip is mounted on a supporting member 14 by means of two machine screws 15 passing through suitable holes in said clip and supporting member. Insulating plates 17 and 18 separate the clip and the heads of the screws respectively, from the supporting member, and fiber washers 19 insulate the portion of the screws passing through the supporting member 14. The contact brush 20 usually of carbon or other suitable material, slides in the passageway 11 and is resiliently pressed against the commutator 21 (see Fig. 2) by a wire spring 22. The spring comprises a stationary finger 23 lying against the surface of the clip 10 and engaging the nut On one of the screws 15 so as Specification of Letters Patent.

Application filed July 17,

to be supported thereby as clearly indicated 111 Fig. 2, a coil of several turns, of a height equal to that of the car 12, and the finger 24 extending from the upper end of the coil nto sultable engagement in a small notch 1n the butt of the brush. One of the screws 15 holding the clip 10 is equipped with two nuts and extends up from the surface of the clip far enough to allow the terminal contact of the flexible cable 25 reaching to the brush 20 and also the terminal contact of the lead wire 26 supplying current to the armature, to he slipped over the screw on top of one of the nuts and firmly clamped in positlon by tightening the other nut on top of that. This screw, therefore, serves both as a reta1n1ng member for the clip 10 and a binding post for the electrical connections, while the other screw fastens the clip and also provides'a support or abutment for the stationary finger of the spring 22.

In assembling the brush holder in the easing 27 of the electrical tool illustrated, the supporting member 14 is in the shape of a ring having sliding engagement in the cylindrical portion 28 of the casing of the tool. The ring 14 may be supported in operative position by any suitable means. I have illustrated a shoulder formed on the casing 27 against which the ring may be pushed and a resilient wire retaining ring 29 adapted to e sprung into a suitable groove in the easing 27 and to hold the ring 14 in position. I have illustrated two brush holders supporting brushes which engage the commutator 21 at diametrically opposite points. It will be obvious that there may be any desired 'number of brushes depending upon the type of motor used. My device is built up of a minimum number of parts which are quickly and easily formed from ordinary sheet metal and spring wire.

While I have shown and described in detail a preferred embodiment of my invention, it should be clearly understood that the description is only for purpose of illustration and that many improvements and modifications will naturally occur to those skilled in the art. I aim in the subjoined claims to cover all such legitimate modifications and improvements.

I claim as my invention- 1. A brush holder for electrical machinery comprising, in combination, a one piece sheet metal cli having a transverse guideway at one em, a retaining member extending through said clip, a. nutthreaded on the end of said retaining member to clamp said clip in position, and a spring having a stationary end engaging said nut so as to be supported thereby.

2. A brush holder comprising a plain strip of metal having one end bent repeatedly at an angle to define a polygonal guideway transverse to the long dimension of the strip the leading edge of said bent end being on a wall of said guideway projecting toward the plain portion of the strip.

3. A brush holder comprising a. plain strip of metal having one end bent repeatedly at an angle so that the leading edge is on a portion projecting toward the unbent portion of the strip whereby to define a polygonal guideway transverse to the long dimension of the strip, and an ear at the end of the strip opposite the guideway bent up out of the plane of the strip on the same side as the guideway.

4. In an electrical machine, a cylindrical casing, an annular supporting member in said casing. said casing having a shoulder abutting said supporting member, an annular groove in said casing and a retaining member in said groove for holdin said annular supporting member between itself and said shoulder, and brushes supported by said annular member.

5. In an electrical machine, in combination, a brush, a sheet metal clip forming a uide for said brush, a supporting member, p ates of insulating material on both sides of said supporting member, a retaining member passing through said insulating plates, said support and said clip, and a spring having a stationary end, the projecting end of said retaining means being adapted to serve as a support therefor.

6. In an electrical machine, in combination, a brush, a sheet metal clip bent to formv a guide for said brush, a support,.a plate of insulating material between said support and said clip, a second plate of insulating material on the opposite side of said support, and a retaining member passing through said insulating plates, support and clip and projecting beyond the face of said clip to serve as a binding post for electrical connections.

7. In an electrical machine, a. cylindrical casing, an annular supporting member in said casing. said casing having a shoulder abutting said supporting member, an annular groove in said casing and a retaining member in said groove for holding said annular supporting member between itself and said shoulder, a plurality of brush holders insulated from and supported by said annular supporting member, and brushes in said holders,

8. A brush holder comprising a single strip of sheet metal substantially rectangular in shape and bent back upon itself at one end to provide a transverse guideway for a brush and having a member rising from the other end, and a spring mounted on said member having a free end engaging a brush operating in said guideway.

9. A brush holder comprising a single strip of sheet metal bent back upon itself at one end to provide a transverse guideway for a brush and provided at the other end with a member rising from the plane thereof, a spring mounted on said member and having a free end engaging a brush operating in said guideway, and a retaining memher at the intermediate portion of the holder to hold the same in position.

10. A brush holder comprising a onepiece sheet metal clip of substantially rectangular shape conformed to provide at one end a transverse guideway for a brush and provided at the opposite end with a member rising from the plane thereof, a coiled spring mounted on said member and having a free end engaging a brush operating in said guideway, and a retaining member at the intermediate portion of the clip to hold said clip in position, said retaining member constituting a support for the stationary finger of the coiled spring.

11. A brush holder comprising a single sheet metal strip bent to provide a brush guideway and having a member rising from the plane of the strip, a spring mounted on said member and having an end engaging a brush operating in said guideway, a. binding post for electrical connections and a retaining means for securing the holder to a support comprising a bolt extending therethrough and constituting a support for the spring.

12. In an electrical machine, the combination of a brush, a spring and a one-piece sheet metal plate bent to fo m a guideway for said brush and a support ior said spring, and an attaching member extending through said plate to fasten the same to a support, the projecting end of said attaching member constituting an abutment'for the stationary finger of said spring.

13. In an electrical machine, the combination of a support, a brush, a sheet metal plate provided with a guideway adapted to support and guide said brush, and means for yieldingly urging said brush into operating position together with means common to saidto provide-a four walled guideway extendthe main portion thereof to provide a subing from side to side of the strip. stantially completely walled guideway ex- 15. A brush holder formed of a single tending from side to side of the strip. 10

strip of metal, the side edges of which are In testimony whereof, I have hereunto 5 approximately straight and having at least set my hand.

one end cut approximately on a straight line,

said. strip bemg turned over at the end on ALBERT THOMAS LOCHNER. 

